Disc drive machines record and reproduce information stored on concentric circular information storage tracks on magnetic information storage discs. Conventional Winchester type disc drives include a plurality of vertically aligned rotating information storage discs, each having at least one associated magnetic head that is adapted to transfer information between the disc and an external system. Each head is carried by an elongated flexure arm. The flexure arms are vertically aligned and are each attached to a common head positioner assembly. The head positioner assembly is adapted to move the heads back and forth in unison across the face of the vertically aligned discs, The head positioner assembly may be either rotationally mounted, or may take the form of a linear carriage that is free to move back and forth along a single axis. In either case, the head positioner assembly is adapted to precisely position the heads relative to the magnetic discs.
During operation, the read/write heads and the flexures are occasionally known to fail and require repair. Therefore, it is desirable to provide a flexure mounting structure that allows replacement of individual heads. To minimize the skill and time required to replace individual heads, it is desirable to provide a mechanism for removing individual flexures without requiring the disassembly of the entire head positioner assembly or the removal of all of the head arms.
One conventional manner for mounting the head arms utilizes a head positioner assembly having a plurality of vertically aligned ears. Each head arm is than mounted to a single ear with one or two screws extending vertically through the vertically aligned ears to hold all of the head arms together. Such an approach has several disadvantages. First, anytime a single one of the read/write heads requires replacement, all of the head arms must be disassembled.
To maximize efficient information storage on the disc, it is important that once set, the heads move laterally as little as possible relative to the head positioner assembly. Movements on the order of several millionths of an inch can cause difficulties. However, in the mounting arrangement described above, thermal expansions and contractions within the screw and head positioner assembly can induce stresses within the screw and allow relieving of the screw's own internal torsional stresses induced while tightening that cause the screw to unwind a minute amount which results in lateral head movements large enough to cause troubles. Therefore, during production, the disc drive must be run through at least one thermal baking and cooling cycle to eliminate thermal stresses within the disc drive components including the flexure mounting arrangement. The thermal baking and cooling cycle is extremely time consuming and creates one of the major delays on a production line. Therefore, it is desirable to provide a flexure mounting structure that does not require thermal baking and cooling to minimize lateral movements of the heads.